Biological machines, and biomolecular motors in particular, have been refined through eons of evolution. Individual (or a very small number of) motors can transport cellular components within a cell, while ensembles of very large numbers of motors are arranged to move the largest creatures on earth. Nanoscale engineering by humans can be greatly enhanced by assimilation of biological specialization already achieved through natural evolution, and by envisioning additional modifications through molecular genetics.
Increasing demand for in situ characterization and quantification of samples in complex systems has stimulated the development of miniaturized chemical analysis systems that automatically perform multiple steps such as sampling, transport, separation, and detection. See Hess, et al., J. Biotechnol. 82:67–85 (2001); Schmidt, et al., Nano Lett. 2:1229–1233 (2002); and Soong, et al., Science 290:1555–1558 (2000). Crucial to these systems is the availability of nano-mechanical devices, i.e., nanoscale motors, that provide the necessary locomotive forces. Because production of nanoscale motors has proven challenging, a recent focus has been on adapting the highly efficient, naturally occurring nanoscale motor proteins kinesin and myosin, coupled with microtubules and actin filaments, respectively. In vitro interactions between actin and myosin, two major muscle proteins, powered by the hydrolysis of adenosine triphosphate (ATP), can produce movement and force in the same way they drive muscle contractions. The success of a device comprising the actomyosin system depends on the proper interfacing/immobilization of the proteins to synthetic nanomechanical components. Surfaces used should be biocompatible and patterned in a way that would allow ordered and controllable actomyosin, kinesin/microtubule interactions. Nanostructured surfaces having submicrometer grooves have been produced, using electron beam lithography and UV photolithography, to restrict actomyosin motility to specified areas. Nicolau, et al. Biophys. J., 77:1126–1134 (1999); Suzuki, et al., Biophys. J. 72:1997–2001 (1997); and Bunk, et al., Biochem. Biophys. Res. Commun. 301:783–788 (2003). Sufficiently narrow grooves constrain filament motion to a track and minimize the number of filaments that change direction. Motor proteins, however, were located both within and between tracks, rendering the complete restriction of the actomyosin interaction to the patterned areas somewhat difficult to achieve. We have now discovered certain improvements in the art of nanoscale motors and devices.